Dates:

March 27th, 2019 3:59 AM - 4:49 AM PDT

What happened:

Customers could not start tests or new tunnels. Both the SauceLabs UI and saucelabs.com were unresponsive.

Why it happened:

The normal constraints on the volume of concurrent tests allowed to run on our service were inadvertently removed by a configuration change. Without these constraints, the number of running tests rapidly increased to the point that our service became unresponsive.

How we fixed it:

We corrected this by returning the subsystem config to its proper value and restarting the subsystem.